From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B08FFC54798 for ; Fri, 23 Feb 2024 11:20:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=YJ5f1Jz+6POuJ1ufl/zbJRX8nqsgUKGYCbVY/ihPxnU=; b=fv83KYnnk0iqQA jIwfHO5B3+NxWgu2KyhrrSQvOL8vommQyoGp0OlmFghxuwwkq3nt4+n00qzlSCIMrOQBCJd7osXqz Y6MFKyaL1lRLZlH5+KnysyCoZ2iMq+odQ6cRUSqxmuapFt6SY6K+KUGzNxUTeUVqoMsHwMvUgNt5R VSLZt+l/eIYU65MM6uBzCJ2QLntiKe41z+ex19iIhOhlyEkyvbKoyaPE4HSFzcL/gu3zg5Sikicee CHjes/QQeZuAqEDRtEeVe1lmP2UL5AVHA9ply9cB337PsA6Ox1p2qybvSu6psUKa5FtMYOe1W2fPM NdX9qf6rBHkyr+Itrk9g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rdTaq-000000095ct-1Uah; Fri, 23 Feb 2024 11:19:52 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rdTa9-000000095VZ-30YW for linux-arm-kernel@lists.infradead.org; Fri, 23 Feb 2024 11:19:46 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 16C3E633B5; Fri, 23 Feb 2024 11:18:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5627C433C7; Fri, 23 Feb 2024 11:18:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708687135; bh=DDeLOBkL7z6riCGOV97XoJTY1vZaFPeBQPATuj2ulYg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=gQJwTg+DR9eBYHrl/ADjvl6lI9Vf1UqIjNUSfmAHFFQcC7Rcxbar7XlUSEn5J+yHu Mhhgzmb/yc/ts8Db5mpYWBgzh/rV/06HP3eNGeGEcq/2CRgeifmkAcGmaBLlYsXPkF oV/QUKA/Olz+pTPM7qNSOzFvMvLvFUmKSigeL2Slb+ZZs9VB30yphngm4ASU21d0TU Ed2Qs2c1XwAhmF2UNNHh63HUB+Q+ABG/Q3Exw3pTqM7K1rggVAIefCM7s3YoDeKVJG x3aSLeQeuSOUMnN2NjUjnZ9nomDec/Z3QBAvx0q2HVFG5FTV760ipiDIOSLJmLNpwO VbF3GFox8/NOg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rdTZt-00642G-4l; Fri, 23 Feb 2024 11:18:53 +0000 Date: Fri, 23 Feb 2024 11:18:51 +0000 Message-ID: <86plwn2ztw.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Catalin Marinas , Will Deacon , Oliver Upton , James Morse , Suzuki K Poulose , Jonathan Corbet , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dave Martin , kvmarm@lists.linux.dev, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v4 12/14] KVM: arm64: Support FEAT_FPMR for guests In-Reply-To: <20240122-arm64-2023-dpisa-v4-12-776e094861df@kernel.org> References: <20240122-arm64-2023-dpisa-v4-0-776e094861df@kernel.org> <20240122-arm64-2023-dpisa-v4-12-776e094861df@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: broonie@kernel.org, catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, corbet@lwn.net, shuah@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, dave.martin@arm.com, kvmarm@lists.linux.dev, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240223_031909_963161_07EC8E20 X-CRM114-Status: GOOD ( 32.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 22 Jan 2024 16:28:15 +0000, Mark Brown wrote: > > FEAT_FPMR introduces a new system register FPMR which allows configuration > of floating point behaviour, currently for FP8 specific features. Allow use > of this in guests, disabling the trap while guests are running and saving > and restoring the value along with the rest of the floating point state. > Since FPMR is stored immediately after the main floating point state we > share it with the hypervisor by adjusting the size of the shared region. > > Access to FPMR is covered by both a register specific trap HCRX_EL2.EnFPM > and the overall floating point access trap so we just unconditionally > enable the FPMR specific trap and rely on the floating point access trap to > detect guest floating point usage. > > Signed-off-by: Mark Brown > --- > arch/arm64/include/asm/kvm_arm.h | 2 +- > arch/arm64/include/asm/kvm_host.h | 3 ++- > arch/arm64/kvm/emulate-nested.c | 8 ++++++++ > arch/arm64/kvm/fpsimd.c | 2 +- > arch/arm64/kvm/hyp/include/hyp/switch.h | 7 ++++++- > arch/arm64/kvm/sys_regs.c | 11 +++++++++++ > 6 files changed, 29 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 7f45ce9170bb..b2ddb6165953 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -103,7 +103,7 @@ > #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) > > #define HCRX_GUEST_FLAGS \ > - (HCRX_EL2_SMPME | HCRX_EL2_TCR2En | \ > + (HCRX_EL2_SMPME | HCRX_EL2_TCR2En | HCRX_EL2_EnFPM | \ No. We don't do that anymore. This can only be enabled if the guest has it advertised via ID_AA64PFR2_EL1.FPMR. > (cpus_have_final_cap(ARM64_HAS_MOPS) ? (HCRX_EL2_MSCEn | HCRX_EL2_MCE2) : 0)) > #define HCRX_HOST_FLAGS (HCRX_EL2_MSCEn | HCRX_EL2_TCR2En | HCRX_EL2_EnFPM) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index c4fdcc94d733..99c0f8944f04 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -384,6 +384,8 @@ enum vcpu_sysreg { > APGAKEYLO_EL1, > APGAKEYHI_EL1, > > + FPMR, > + > /* Memory Tagging Extension registers */ > RGSR_EL1, /* Random Allocation Tag Seed Register */ > GCR_EL1, /* Tag Control Register */ > @@ -544,7 +546,6 @@ struct kvm_vcpu_arch { > enum fp_type fp_type; > unsigned int sve_max_vl; > u64 svcr; > - unsigned long fpmr; > > /* Stage 2 paging state used by the hardware on next switch */ > struct kvm_s2_mmu *hw_mmu; > diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c > index 431fd429932d..3af5fd0e28dc 100644 > --- a/arch/arm64/kvm/emulate-nested.c > +++ b/arch/arm64/kvm/emulate-nested.c > @@ -67,6 +67,8 @@ enum cgt_group_id { > CGT_HCR_TTLBIS, > CGT_HCR_TTLBOS, > > + CGT_HCRX_EnFPM, > + > CGT_MDCR_TPMCR, > CGT_MDCR_TPM, > CGT_MDCR_TDE, > @@ -279,6 +281,11 @@ static const struct trap_bits coarse_trap_bits[] = { > .mask = HCR_TTLBOS, > .behaviour = BEHAVE_FORWARD_ANY, > }, > + [CGT_HCRX_EnFPM] = { > + .index = HCRX_EL2, > + .mask = HCRX_EL2_EnFPM, > + .behaviour = BEHAVE_FORWARD_ANY, This is obviously incorrect. > + }, > [CGT_MDCR_TPMCR] = { > .index = MDCR_EL2, > .value = MDCR_EL2_TPMCR, > @@ -478,6 +485,7 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = { > SR_TRAP(SYS_AIDR_EL1, CGT_HCR_TID1), > SR_TRAP(SYS_SMIDR_EL1, CGT_HCR_TID1), > SR_TRAP(SYS_CTR_EL0, CGT_HCR_TID2), > + SR_TRAP(SYS_FPMR, CGT_HCRX_EnFPM), > SR_TRAP(SYS_CCSIDR_EL1, CGT_HCR_TID2_TID4), > SR_TRAP(SYS_CCSIDR2_EL1, CGT_HCR_TID2_TID4), > SR_TRAP(SYS_CLIDR_EL1, CGT_HCR_TID2_TID4), > diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c > index 6cf22cd8f020..9e002489c843 100644 > --- a/arch/arm64/kvm/fpsimd.c > +++ b/arch/arm64/kvm/fpsimd.c > @@ -152,7 +152,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) > fp_state.sve_vl = vcpu->arch.sve_max_vl; > fp_state.sme_state = NULL; > fp_state.svcr = &vcpu->arch.svcr; > - fp_state.fpmr = &vcpu->arch.fpmr; > + fp_state.fpmr = (unsigned long *)&__vcpu_sys_reg(vcpu, FPMR); > fp_state.fp_type = &vcpu->arch.fp_type; > > if (vcpu_has_sve(vcpu)) > diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h > index 27fcdfd432b9..abf785c473d0 100644 > --- a/arch/arm64/kvm/hyp/include/hyp/switch.h > +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h > @@ -370,10 +370,15 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) > isb(); > > /* Write out the host state if it's in the registers */ > - if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) > + if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) { > __fpsimd_save_state(&(vcpu->arch.host_uw->fpsimd_state)); > + if (cpus_have_final_cap(ARM64_HAS_FPMR)) Same thing as above: this cannot be unconditional. > + vcpu->arch.host_uw->fpmr = read_sysreg_s(SYS_FPMR); > + } > > /* Restore the guest state */ > + if (cpus_have_final_cap(ARM64_HAS_FPMR)) > + write_sysreg_s(__vcpu_sys_reg(vcpu, FPMR), SYS_FPMR); > if (sve_guest) > __hyp_sve_restore_guest(vcpu); > else > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 38503b1cd2eb..216eac44c124 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -2067,6 +2067,15 @@ static unsigned int hidden_user_visibility(const struct kvm_vcpu *vcpu, > .visibility = hidden_user_visibility, \ > } > > +static unsigned int fpmr_visibility(const struct kvm_vcpu *vcpu, > + const struct sys_reg_desc *rd) > +{ > + if (cpus_have_final_cap(ARM64_HAS_FPMR)) > + return 0; Same thing. > + > + return REG_HIDDEN; > +} > + > /* > * Since reset() callback and field val are not used for idregs, they will be > * used for specific purposes for idregs. > @@ -2463,6 +2472,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { > { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, > { SYS_DESC(SYS_CTR_EL0), access_ctr }, > { SYS_DESC(SYS_SVCR), undef_access }, > + { SYS_DESC(SYS_FPMR), access_rw, reset_unknown, FPMR, > + .visibility = fpmr_visibility }, > > { PMU_SYS_REG(PMCR_EL0), .access = access_pmcr, .reset = reset_pmcr, > .reg = PMCR_EL0, .get_user = get_pmcr, .set_user = set_pmcr }, > Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel